Factory A/C or aftermarket.....

[stope4]

Andy, this is getting off topic but I think what you are experiencing has to do with how much air is blowing over your condenser in front of the radiator. If you sit at idle in your driveway and spray water on the condenser, I believe the 134a will cool at idle just as good as R12. The problem, how do we get there when we are idling in traffic. You need a stronger gan and more than likely a bigger condenser.